Differential hoisting mechanism



(No Model.) 3 Sheets-Sheet 1..

F. OLEMONS.

DIFFERENTIAL HOISTING MECHANISM.

No. 872,839. Patented Nov. 8, 1887.

(No Model.) 3 Sheets-Sheet 2.

G. ROLEMONS. DIFFERENTIAL HOI$TING MECHANISM. No. 372,839.. Patented Nov. 8 1887.

(No Model.) v 3 Sheets-Sheet 3. G. P. OLEMONS.

DIFFERENTIAL HUI STING MECHANISM.

No. 372,839. Patented NOVF'B, 1887.

NQPETERS. Pholodjlhngnplmr. Washinglon. D. C.

UNITED STATES PATENT rricn.

GEORGE F; oLEMoNs, or SPRINGFIELD, MASSACHUSETTS.

DIFFERENTIAL HOISTING MECHANISM.

SPECIFICATION forming part of Letters Patent No. 372,839, dated November 8, 1887. Application filed February 19, 1887. Serial No. 228,160. (No model.)

To all whom it may concern:

Be it known that I, GEORGE F. GLEMoNs, a citizen of the United States, residing at Springfield, in the county of Hampden and State of Massachusetts, have invented new and useful Improvements in Differential Hoisting Mechanism, of which the following is a specification.

This invention relates to differential hoist ing-pulleys, the object being to provide an improved construction of this class of pulleys by combining with two pulleys or drums which have a connection by means of a spur and an internal gear an improved shaft by which said pulleys are operated; and the invention consists in the peculiar construction and arrangement of the parts of the hoisting mechanism, all as hereinafter fully described, and pointed out in the claims.

In the drawings forming part of this specification, Figure 1 is a side elevation of a differential hoisting-pulley constructed according to my invention, the chain-pulleys and the hand-chain wheel being shown in section and parts of the chains being shown thereon. Fig. 2 is a plan view of the supporting-yoke of the pulley shown in Fig. 1, the top hook not be-' ing shown. Fig. 3 is a side elevation of a hoisting device embodying my improvements,

' are the spur'and internal gears;

in which drums or spools are employed, on which the hoisting chains or ropes are wound, instead of pulleys, as shown in Fig. 1, said figure showing said drums or spools in sec-' tion, means for disconnecting the windingspools, and a crank for turning the shaft, which is there shownmounted in standards. Fig. 4 is a detail view of a portion of the mechanism shown in Fig. 3 and is hereinafter fully described. Figs. 5 and 6 are side elevations of the pulleys or end views of the spools on which Fig. 7 is a perspective view of the construction shown in Fig. 1 with the frame or yoke removed, and showing the lifting and hand chains thereon in operative positions.

In the drawings, 3 indicates an eccentricshaft, which is so designated because it is made with two eccentrics, 4, projecting laterally from opposite sides thereof, and said eccentrics may be of equal or unequal diameter; but in any case the longitudinal center lines of both of said eccentrics are on opposite sides of the axial line of said shaft and at equal distances from said line. Said eccentricshaft is hung in suitable bearings in a frame, 5, Figs. 1 and 2, when used in a differential-pulley construction similar tothat there shown, which is portable and adapted to be suspended in any required-location for hoisting articles. Said frame has an encircling band thereon surrounding the chain-pulleys, and has a hook, 6, thereon, a portion of which is broken off, as there shown. When said shaft 3is employed in fixed hoisting devices, it is hung in proper bearings in vertical standards 7, as shown in Fig. 3. As means for imparting a rotary motion to said eccentric-shaft, the chain-wheel 9, fixed on the end of thelatter, asin Fig.1, having ahand-chain, 10, looped around it and hanging therefrom in the usual manner, is employed preferably in the construction shown in Fig. 1; but in that shown in Fig. 3 the crank 12 there shown is more convenient, as the hoisting device shown in said gure is fixed. It

is obvious, however, that any suitable means may be employed for giving rotary motion to said shaft. 7

On the above-described eccentric-shaft 3 are placed side by side, as shown, either two chainpulleys, 13, or spools 14 and 20, it being practically immaterial whether the chainpulley.

or the spool be used, on whichthe chain 15 or cords or ropes 16 are wound, as both spools and chain-pulleys have identically the same function in the device. Each of said chainpulleys and winding-spools is located on one of the eccentrics on the said shaft 3, as shown, side by side or end to end, and the adjoining sides of said pulleys or the adjoining ends of said spools have an interlocking geared connection, as below described. On one of said pulleys or spools is fixed a spur-gear, 17, as shown in Fig. 5, and on the adjoining pulley or spool is fixed an internal gear, 18, as shown in Fig. 6, the internal diameter of the gear 18 being greater than the external diameter of said spur-gear 17, the latter having a position within said gear 18, and, owing to the position which it is made to assume by the eccentric on which the pulley to which it is attached is placed, it has a portion of its periphery in engagement with said internal gear.

The construction shown in Fig. 1 involves the employment of two chain-pulleys, on each of which is rigidly fixed either a spur or internal gear, as above described. The construction shown in Fig. 3 involves the employment of one winding-spool 14, having said fixed gear 17 thereon, of a spool-sleeve, 19, having its bearing on one of said eccentrics 4 on shaft 3, having on its end adjoining the end of said spool 14 said internal gear, 18, which engages, as aforesaid, with said gear on the spool, and on said sleeve 19 is placed the spool 20, having a cup-shaped end, 21, whose border flares slightly outward and has an internal diameter adapting it to fit over the aforesaid internally-geared end of said sleeeve 19, and,owing to the form of the latter and of that portion of the spool 20 which is shown in engagement therewith in Fig. 3, the said spool and sleeve are capable of a frictional engagement, whereby the spool 14 and the spool 20 are made to have such rotary motions by the action of the shaft 3, as below described, as are given to the chain-pulleys in the construction shown in Fig. l. The said spool 20, Fig. 3, is capable of a free rotary movement on the said sleeve 19 when disengaged from the end of the latter in which is said internal gear. The spool 20 is given a longitudinal movement on said sleeve 19 to engage it with and disengage it from said sleeve by the below-described means. The said spool 20 has a wide groove, a, around it, near one end. In the end of an arm, I), which is bolted to the upper end of one of said standards 7, is hung a shaft, 22, having an eccentric, 23, (see Fig. 4,) formed on its lower end. The said shaft 22 stands at right angles to the shaft 3 and about centrally between the sides of the said groove to in the spool 20, and has secured on said eccentric on its end a friction-wheel, 24:, which is free to rotate on said eccentric, and whose diameter is nearly equal to the width of said groove a. The outer end of said shaft 22 has fixed thereon a handle, 25, by which the shaft is turned. Fig. 4 is a somewhat enlarged plan view of a part of the grooved portion of said spool 20, showing in connection therewith the eccentric bearing end of the shaft 22 in sect-ion, said eccentric 23, and the said friction-wheel 24.

In Fig. 3 the spool 20 is shown in engagement with the end of the sleeve 19 and the position of the handle 25 when the frictionwheel 21L is held against the spool 20 by the cocentric 23 on shaft 22. By turning said handle 25 either to the right or left the frictionwh'eel 24 is moved against one side of the groove a and acts to draw the spool 20 out of engagement with the sleeve 19, but a slight movement being necessary to this end.

The above-described construction (shown in Fig. 3) provides means for the disengagement of the winding-spools 14 and 20 from each other after the ropes 16, having some object attached thereto to be lifted, have been wound onto the spools, whereby said spools are freed from each other, thus permitting an object which has been lifted,as aforesaid, to be quickly dropped by the free rotation of the windingspools, while the shaft 3 and crank 12 remain stationary.

Referring to Figs. 1 and 7, the latter illustrating in perspective view the two chain-pulleys 13 and the hand-chain wheel 9, together with the chains which operate thereon, it is seen that the hand-chain 10 rests pendent by its weight on the wheel 9, (the latter being fixed on the shaft 3,) so that by pulling on either side of chain 10 wheel 9 and the shaft 3 are given a rotary motion. The chain 15, whose two ends hang down one from each of the pulleys 13, has a slack loop, as shown, between the flanges of each of said pulleys, and each of said two ends is provided with a hook, as shown, whereby suitable connection is made with anything that it is desired to lift by the use of the device.

In practice the adjustment of the longitudinal center line of the eccentrics 4: relative to the axis of the shaft 3 is such as to carry said center line to one side of the axis of said shaft sufficiently to cause the said spur and internal gears to have a proper engagement. When the shaft 3 is rotated, the differential rotary motion thereby given to the chain-wheels 13 will cause the latter to rotate in opposite directions. A resisting force-as, for instance, a weight attached to the chain 15, Figs. 1 and 7, or to the ropes 16, Fig. 3will act on the eccentrics on the shaft 3 in opposite directions, thereby balancing the resistance or weight on the axis of the driving-shaft, so that the leverage acting against the motive power, or that which rotates shaft 3, is only that which is represented by the difference of the length of the radius of the spur-gear 17 and the internal gear, 18.

Owing to the fact, as above stated, that the weight which is applied to the chain-wheels or spools through the chains and cords connected therewith acts on the said eccentrics in opposite directions, a weight lifted by this device will remain in any position when the hand-chain is let go.

The illustration of the adaptation of the principles of the construction which is found in Fig. 3 shows a different way of applying the within-described improved differential hoisting mechanism, the arrangement of the mechanism in said figure being such that the differential elements thereof perform the same functions as those shown in Figs. 1 and 7.

I do not limit myself to the employment of the above-described peculiar differential mechanism-via, the shaft 3, having the said two eccentrics thereon, on each of which is a spool or pulley interconnected by differential gearing, as set forth in connection with the construction shown in the drawingsforsaid differential mechanism, as will be clearly understood by persons skilled in the art of mechanical engineering, is adapted to be applied to elevators and other hoisting apparatus than precisely such as are herein shown.

What I claim as my invention is ICO '1. The combination of mechanism consisting of a shaft, as 3, having thereon two eccentrics projecting laterally from opposite sides thereof, two winding-pulleys, substantially as 5 described, capable of a rotary motion on said eccentrics, having a geared connection with each other by means of a spur-gear and an internal gear, substantially as described, on said pulleys, and suitable means forimparting a I3 rotary motion to said shaft,substantially as set forth. g

2. In combination, a shaft, as 3, having thereon two eccentrics projecting laterally from opposite sides thereof, a winding-pulley I 5 having a spur-gear thereon capable of a rotary motion on one of said eccentrics, a sleeve, as 19, having an internal gear thereon engaging with said spur-gear and capable of a rotary motion on the second of the said eccentrics, a winding-pulley, as 20, capable of a rotary mo- 20 tion on said sleeve and of a frictional engagement therewith, and a cam-shaft, substantially as described, having an engagement with said pulley 20, to move it longitudinally on said sleeve, substantially as set forth.

GEORGE F. OLEMONS. 

